Directional compass



l, 1944.' J. |55 SWART 2,340,512

DIRECTIONAL COMPASS Filed Sept. 25, 1942 may UNITED STATES PATENT Patented Feb. 1, 1944 yihalf `to C. Bland Jamison, Beverly Hills, Calif.

Application September 25, 1942, Serial No. 459,689

OFF-ICE 10 Claims.

This invention relates to directional compasses and, more particularly, it relates to Compasses of the type adapted to be carried in the pocket.

One of the disadvantages of directional compasses of this type presently in use is the inefficient means provided for retaining the needle in stationary position when the device is not in use. The means heretofore provided for this purpose consist largely of resilient levers normally held under tension when the device is not in use, with the result that the levers become deformed and allow the magnetic needle to vibrate when the device is not being used. Another prior art locking means has been a stem operated cam which is not automatic in its operation with the result that the needle is frequently left in unlocked position. Moreover, these prior art devices are relatively expensive to manufacture and assemble and are not conducive to being made of available plastic materials.

It is therefore `among the principal objects of my invention to overcome these shortcomings of prior art Compasses and to provide a compass embodying simple, eicient and automatic means forV locking the magnetic needle in inoperative position when the deviceis not in use as well as novel means for releasing or unlocking the needle whereby to render it operative.

Another object is to provide a compass Whose interior is eiectively sealed against admission of moisture and the like.

Another object of my invention is the provision of a pocket compass whose parts are so designed and associated that substantially the entire device may be made of plastic materials.

Another object is the provision of a compass which may be economically manufactured and assembled, which is extremely durable and which is composed of a minimum number of parts.

Additional advantages are to be derived from my invention, and how those las well as the objects hereinabove specifically enumerated .are attained, will become clear from the ,following detailed explanation of presently preferred embodiments, for which purpose I shall refer to the accompanying drawing, in which:

Fig. l is a top plan View with a part being broken away for illustrative purposes;

Fig. 2 is a section on line 2 2 of Fig. 1, show ing a part in elevation and showing the device with the parts held in inoperative or stationary position;

Fig. 3 is a view similar toriig. 2 .but snowing the parts in unlocked or operative position;

Fig. 4 is a section on line 4 4 oflFig. 2;

(Cl. `Sli- 222) Fig. 5 is a fragmentary vertical sectional view showing a variational form;

Fig. 6 is a fragmentary vertical section showing a further variational form; and

Fig. '7 is a fragmentary side elevation showing the device of Fig. 6 in inoperative position.

Referring now to the drawing, I show in Figs. l-4 inclusive, a preferred form of directional compass embodying my invention, wherein the numeral 5 denotes a body having a circular, up wardly opening recess 6 in its top, the bottom wall 'I of the body having a central opening 8 within which is suitably secured the bottom end of a pivot pin I0. Opening 8 is provided through a relatively thickened portion of bottom wall l to provide firm mounting for the pin IE. A pair of d-iametrically spaced holes II of curved plan section are provided through the bottom Wall l for the purpose to be described. While I prefer to make body 5 of plastic material such `as Lucite or Tenite it will be understood of course that other materials may be used if desired.

, Within the recess 6, and with its peripheral edge bearing against the top surface vof wall "I, I provide a resiliently iiexible disc or inner wall member I4, whose central portion is upwardly vaulted as best shown in Fig. 2. On the top face of disc i4 there is suitably applied, as by printing, directional indicia I5 denoting the points of the compass. A central opening I6 is provided through the disc to pass the upper tapered -end of the pivot pin I9.

Y Projecting downwardly from the underface of disc .I there are two lugs I'I shaped to conform to holes I I, these lugs projecting through said holes. Each lug has, adjacent its lower end, a radially disposed recess I 8 Within which pivotally rest the opposite ends of a hook I9 from which a chain 23 is suspended, the lower end of the chain carrying a knob 2| for the purpose to be described. I find that a exible plastic such as Lucite or "Tenite is Well suited for the material of disc I4.

A cover member generally designated by the numeral 25 has a transparent top wall `2l and a circuiar side wall 26. This cover member is preferably made of a transparent plastic such Vas Lucite so that the top wall 2'I provides a crystal through which the Adirectional indicia may be viewed. Its side Wall 26 frictionally engages the side wall of the body recess 6. A central recess 23 is provided in the undersurface of wall 2l to receive the hub'of the magnetic needle to be described.

While the foregoing description and the annexed drawings serve to explain one operative adaptation of my invention, the broader aspects of my invention, as dened by the following claims, contemplate that the invention may be embodied in other and varying specific struc- Y tures.

projectsto prevent longitudinal movement of theJ disc relative to the body, the periphery of the disc'` bearing. against the side wall 2S within the recess. In Fig. 5 I show, incorporated in my device, a means to assure a fluid-tight seal between lugs I1 and openings I I. Here I provide a-recess 5@ in the undersurface of b ody wall 1 and provide a substantially rigid washer 5I carried by the lugs l1, as by a friction lt thereon. Between washer 5I and the bottom of recess 58 I interpose a sealing ring 52, of soft rubber or other suitable material. The hook I9 abuts the bottom of washer 5I to prevent downward longitudinal escape of the washer, and, when the device is in inoperative position (Fig. 2) the sealing ring is resiliently compressed between washer 5I and the bottom wall of recess 5D by the resiliency of disc I4.

The device is shown in inoperative position in Fig. 2, and in that position the disc I4 Vis .in its normal, upwardly vaulted shape, thus resiliently holding the hub 33 oli the end of pivot pin IIJ and against the bottom of the recess 28. To release the needle whereby it may pivot about pin ID and with reference to the directional indicia, the user merely grips the chain 2u with the fingers so that the undersurface of body wall 1 rests against the irst finger and knob 2I rests against the little finger. A slight spreading apart of the ngers, or upward movement of the thumb against the body wall 1, causes the body 5 and knob 2l to be moved relatively apart and thus, through the medium of the lugs I1, the disc I4 is flexed to the operative position of Fig. 3, thus releasing the needle for free pivotal movement relative to the directional indicia. Upon subsequent release of the chain the parts automatically return to the inoperative position shown in Fig. 2 by virtue of the resiliency of disc I4.

From the vforegoing it will be seen that the i flexible disc I4 remains in its normal, unflexed condition at all times when the device is not in operationwhich is normally the majority of the time-and is only held eXed during operation. It is impossible to leave the device in operative position, wherein'the needle is free to vibrate, inasmuch as the disc I 4, by virtue of its :resiliency, automatically returns to the position or" Figj2 upon release of the chain.

In Figs. 6 and 7 I show a variational form of disc flexing means, in which the parts are as before described and are given like numerals, except that in lieu of the chain pull 29 I provide a swingable U-shaped handle 60 having inwardly, oppositely disposed projections 6l spaced from the ends 62, which projections are pivotally mounted in recesses E3 provided in lugs Il. When the device `is in inoperative position, the parts are as shown in Fig. 7. To flex disc I4 towards the body wall 1, the handle is swung to the position of Fig.

6 and in doing so ends 62 of the handle move against body wall 1 causing the projections tl to slide Ythe lugs I1 outwardly, thus exing disc I4 to free needle 3S. In the position of Fig. 6, the ends of the handle lit in recesses 65.

I claim:

1. Acompass comprising a body having a cylindrical side wall and a bottom wall dening an upwardly opening recess, a transparent cover carried by the body in position overhanging the recess, a resiliently flexible upwardly vaulted disc disposed within the recess with its peripheral portion bearing against the bottom wall, direction Y indicia on the top face of the disc, there being a central opening in the disc, a pivot pin secured to the bottom wall and projecting upwardly through the central opening, a magnetic needle having a hub pivoted on the upper end of the pin for movement relative to the direction indicia, said hub being normally resiliently urged against the cover by the disc whereby to restrain pivotal movement of the needle, and means for flexing the central portion of the disc towards the bottom wall whereby to free the hub from engagement with the cover and allow free pivotal movement of the needle.

2. A compass comprising a body having a cylindrical side wall and a bottom wall defining an upwardly opening recess, a crystal member overhanging the recess, said member having an annular depending ange frictonally engaging the body side wall, a marginal recess in the inner surface of the flange, a resiliently flexible, upwardly vaulted disc having its peripheral edge disposed in the last-named recess, there being a central opening in the disc, directional indicia carried on the upper face of thedisc, a pivot pin secured to the bottom wall and projecting upwardly through the central opening, a magnetic needle having a hub pivoted on the upper end of the pin for movement relative to the direction indicia, said hub being normally resiliently urged against the cover by the disc whereby to restrain pivotal movement of the needle, and means for flexing the central portion of the disc towards the bottom wall whereby to free the hub from engagement with the cover and allow free pivotal movement of the needle.

3. A compass comprising a body having a cylindrical side wall and a bottom wall dening an upwardly opening recess, a transparent cover carried by the body in position overhanging the recess, a resiliently exible upwardly vaulted disc disposed within the recess with its peripheral portion bearing against the bottom wall, direction indicia on the top face of the disc, there bemg a central opening in the disc, a pivot pin secured to the bottom wall and projecting upwardly through the central opening, a magnetic needle having a hub pivoted on the upper end of the pin for movement relative to the direction indicia, said hub being ,normally resiliently urged against the cover by the disc whereby to restrain p1vota1 movement of the needle, an opening through the bottom wall of the body, and means for flexing the central portion of the disc towards the said bottom wall, the last-named means including a lug carried by the disc and projecting through the last-named opening.

fl. A compass comprising arbody having a cylindrical side wall and a bottom wall dening an upwardly opening recess,a transparent cover carried by the body in position overhanging the recess, a resiliently flexible upwardly vaulted disc disposed within the recess with its peripheral portion bearing against the bottom wall, direction indicia on the top face of the disc, there being a central opening in the disc, a pivot .pin secured to the bottom wall and projecting upwardly through the central opening, a magnetic needle having a hub pivoted on the upper end of the pin for movement relative to the direction indicia, said hub being normally resiliently urged against the cover by the disc whereby to restrain pivotal movement of the needle,` an opening through the bottom wall of the body, means for flexing the central portion of the disc towards the said bottom wall, the last-named means including a lug carried by the disc and projecting through the last-named opening, a flexible link secured at one end to the lug, and a knob carried by the other end of the link, whereby upon relative movement of the body and knob away from each other the lug is pulled downwardly to downwardly ex the central portion of the disc.

5. The device of claim l wherein the lastnamed means includes a rpull member operatively connected to the disc.

6. A compass of the class described, comprising a housing presenting substantially parallel vertically spaced top and bottom walls, an upwardly vaulted resiliently iiexible disc interposed therebetween, a pivot pin carried by the bottom wall and projecting upwardly through the disc, a magnetized needle member pivotally mounted on the upper end of the pin, said needle member having a hub portion normally resiliently held against the top wall by the disc whereby to restrain pivotal movement of the needle with re-y spect to the disc, and means for iiexing the disc towards the bottom wall whereby to free the hub portion of the needle from engagement with the top wall.

7. A compass comprising a case having a bottom wall and a crystal spaced above the bottom wall, a cylindrical side wall, a resiliently exible disc mounted in the case and presenting directional indicia, means preventing movement of the peripheral portion of the disc towards the crystal, said means including an annular shoulder presented by the side wall, and a magnetic needle pivotally mounted in the case for rotative movement relative to the disc, said movement of the needle being controllable by virtue of flexure of the disc.

8. A compass comprising a case having a bottom wall and a crystal spaced above the bottom rwall, an indicia carrying member resiliently mounted in the case for movement between and towards and away from said wall and crystal, a magnetic needle pivotally mounted between the crystal and thev indicia carrying member, said needle being normally frictionally urged against the crystal by the resiliently mounted indicia carrying member, and pull means operatively connected to the outer portion of the indicia-carrying member and extending axially through and slidable with. respect to the bottom wall, said pull means cooperating with the indicia carrying means to move the latter towards the bottom wall whereby to freethe needle for rotative movement with respect to the indiica carrying member.

9. The device of claim 8 which includes cam means associated with the outer end of the pull means, said cam means having camming engagement with the outer surface of the bottom wall whereby to slide the pull means with respect to the bottom wall.

`10. The device of claim 6 wherein the lastnamed means includes a pull member connected at its inner end to the central portion of the disc and slidably projecting axially through the bottom wall, and a cam element operatively associated with the outer end of the pull member.

JAN DE SWART. 

